Detectives have appealed for witnesses to come forward after gas canisters were used in an attempted theft from a cash machine at Thornton Heath Station this morning.
A break-in took place 2am and 4am on Tuesday, 3 June, and British Transport Police officers attended the scene alongside firefighters who made the gas canisters safe.
Detective Inspector Andy Rose, of BTP CID, said: "In the early hours of Tuesday, 3 June, the station booking hall was broken into and the ATM inside was badly damaged in what we believe was an attempted theft.
"However the assailants were disturbed at 4am and left the scene empty-handed.
"When our officers arrived they found the ticket office had been broken into and gas canisters had been used as part of an elaborate attempt to break open the cash machine."
Detectives are currently reviewing CCTV footage from the booking hall and outside the station, while crime scene examiners are searching the station for potential evidence.
Det Insp Rose added: "We believe two men were involved in the incident.
"The first is described as white, in his 40s, 6ft 2ins, slim build, wearing a yellow high visibility jacket, orange high visibility trousers and a black scarf around his face.
"The second man is described as 5ft 8ins, slim build, wearing a blue jacket, blue jeans and black balaclava."
"We want to hear from anyone who noticed any suspicious activity in the area, or has any information that could assist us in our investigation."
Anyone with information is asked to contact British Transport Police on 0800 40 50 40 quoting incident SSUB/B6 of 03/06/2014. Information can also given to the independent charity Crimestoppers, anonymously, on 0800 555 111.